Optimization of multi periods Inventory Routing Problem model with time varying demand

In this paper we consider a multi period Inventory Routing Problem (IRP) that faces time varying demand of multi product from the assembly plant. The problem addressed in this study is a many-to-one distribution network consisting of an assembly plant and many geographically dispersed suppliers where each supplier supplies distinct product to the assembly plant. It is based on a finite horizon, multi-periods, multi-suppliers and multi-products where a fleet of capacitated homogeneous vehicles, housed at a depot, transport parts from the suppliers to meet the demand specified b y the assembly plant in each period. We propose a solution method based on the Variable Neighborhood Search. The algorithm incorporates the Generalised Insertion (GENI) method and the algorithm are run on several problems from the literature and the results are compared with the Genetic Algorithms. VNS performs better on larger problems.